Projection compass



E. E. NORRIS 2,659,972

PROJECTION COMPASS Nov. V24, 1953 Filed J1'1ne`2ly 1950 2 Sheets-Sheet l fw Ap; if@

Nov. 24, 1953 E, E. NoRRls 2,659,972

' PROJECTION COMPASS Filed June 21. 195o 2 sheets-sheet 2 Patented Nov. 24, 1953 UNITED STATES PATENT OFFICE PROJECTION COMPASS Edward E. Norris, Minneapolis, Minn.

Application June 21, 1950, Serial No. 169,397

2 Claims.

` novel devices and combination of devices hereinafter described and dened in the claims.

In the accompanying drawings, which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings:

Fig. l is a side elevational View showing one form of the invention applied to a piece of work in the form of a pipe;

Figs. 2, 3 and 4 are detail views partly in elevation and partly in section taken on the lines 2-2, 3 3 and 4-4 of Fig, 1, on an enlarged scale;

Fig. 5 is a view partly in elevation and partly in section taken on the line 5 5 of Fig. l, on an enlarged scale, the shaft being shown in a perpendicular position relative to the work;

Fig. 6 isa view principally in plan, with the shaft sectioned on the line 6--6 of Fig. 5;

Fig. 7 is a front elevational view of another form of the invention; l

Fig. 8 is a side elevational view of the parts shown in Fig. 7, with a portion thereof broken away and sectioned on the line 8-8 of Fig. 7; and

Fig. 9 is a perspective View of a different form of base.

Referring first to the invention shown in Figs. 1 to 6, inclusive, which includes, as shown in Fig. 1, a primary instrument A and a secondary instrument B. These two instruments are substantially identical, the one with the other, except the mounting thereof. Either one of these instruments may be used for scribing a circle on a piece of work. The mounting of the instrument A limits the smallness of a circle that can be scribed. The instrument B is used for scribing circles smaller than can be scribed by the instrument A.`

The instrument A will rst be described in detail and includes a base I0 in the form of an angle bar, the anges II and I2 of which are turned downwardly with their longitudinal edge portions resting on a piece of work. This piece of work, as shown, is a pipe :e and the base I0 2 extends longitudinally thereof with its apex IU parallel to the axis of said pipe.

The base I0 is rigidly and detachably secured to the pipe x by a pair of chains I3 that extend around said pipe on opposite sides thereof. The uppermost linksI of the chains I3 are held by hooks I4 on the flanges II and I2 at the longitudinal centers thereof. The lowermost links of the chains I 3 are held by a pair of opposite hooks I5 on a nut-acting member I6 having threaded engagement with a hand screw II. This hand screw Il, at its outer end, is swivelled on akchannel block I8, the flanges of which bear on theunder side of the pipe as a base of resistance, see Fig. 5. Obviously, by tightening the hand screw Il, the chains I3 will be drawn tightly around the pipe a: and rigidly hold the base I0 thereon.

Integral with the ange I2 is an upstanding bearing I9, the sides of which are at and extend parallel to the apex I0. A pivot bolt 20, of large diameter, extends through a transverse hole 2| in the bearing I9 and over the base I0 with its axis perpendicular to a plane passing through the apex I il' and'bisecting the angle between the anges II and I2. This bolt 20 has a large head 22 that impinges the outer side of the bearing I6, and the outer end portion of said bolt is of reduced diameter and screw-threaded to afford a stud 23.

A pair ofV clamping discs 24 and 25 have axial holes 26 through which the bolt 26 extends. It

is important to note that the outer end of the bolt 26 terminates short of the outer side of the clamping disc 24, see Fig. 6. The clamping disc 25 impinges the bearing I9 as a base of resistance. In the opposing faces of the clamping discs 24 and 25 is a pair of half seats 2'I that are semi-` circular in cross-section.

A long round shaft 28 in the half seats 2l is held in different endwise adjustments by the clamping discs 24 and 25. This shaft 28 extends through a transverse hole 29- in the bolt 20 and a notch I9 in the front end portion of the base I0. A knurled nut 36 on the stud 23 impinges the outer side of the clamping disc 24 and clamps the discs 2t and 25 onto the shaft 28 and disc 25 onto the bearing I9 and frictonally hold the same from turning. The depth of the half seats 2? is such that the two discs 24 and 25 do not meet when clamped onto the shaft 28, see Fig. 6. The discs 24 and 25 hold the shaft 2B with its axis in the same plane as the apex I0. It is important to note that the diameter of the hole 29 is somewhat larger than the diameter of the 3 shaft 28 to permit the knurled nut 30 to move the discs 24 and 25 axially on the bolt 20 and clamp the disc 25 onto the bearing |9 and to clamp the discs 24 and 25 onto the shaft 28 without interference from said shaft.

The lower end portion of the shaft 28 is tapered to a point 3| at the axis thereof.

Prior to mounting the instrument A on the pipe x, a hole will be punched in said pipe at a predetermined. pointwhich will be the center of a circle to be scribed on said pipe by the instrument A. When mounting the instrument A on the pipe m, the knurled nut 3|) is loosened to permit axial adjustment of the shaft 23 relative to the base lil and its point 3| placed in the center hole punched in the pipe The base lil is next adjusted on the pipe arto-bring the shaft 2B into its correct angular position relative to the apex |B of the base I0. When thebase i0 is properly adjusted on the pipe the hand screwi I1; is operated to' clamp the base |23 onto the pipe and the knurled nut 3|] operated to clamp the discs 2li' and 2-5 onto the shaft 28 and hold the same where adjusted relative to the base lll.. During this adjustment, the shaft 28 is held with its point 3| in the punched center hole. It may be hereA stated that the bottom edge portions of the flanges and I2 will be machined to a true plane, said plane being perpendicular to axis of shaft 28 when the assembly is adjusted and tightened to a position where the 90 mark ondisc 25 aligns with pilot mark 32.

On the top of the bearing le is a pilot mark 32 and on, the periphery of the disc 25 is a cir cumferential scale of degrees 33 reading in opposite direction from zero to 9 0 degrees. When 90 degrees is in registration with. the pilot marit 32, the shaft 28 is perpendicular to the apex iii. Fromy 90. degrees, the scale 3,3- reads in opposite directions to` a second zero which is diamtrically opposite. the first Zero.

A lsleeve 34. on the shaft 28 is normallyv free to float axially and turn. about: the axis of said shaft. This sleeve. 34 is longitudinally slit and provided with a. pair of outstanding ears 35 between which said slit extends. A knurled thumb screw 3S connects the two ears 35. and is operable to draw the. same together and frictionally clamp the sleeve 34 onto the shaft 28. Integral with the upper end of the sleeve 34 is a knurled knob. 31A by which the sleeve 3 4 may be moved on the shaft 28. Formed with the sleeve 34, diametrically opposite the ears 35, is a. radial extension 38..

A depending arm 39 is pivotally attached, at its upper end, to the extension. 38 by a` knurled thumb screw Ml and is normally frictionally clamped` thereon by said screw. A friction holder 4| for a pencil 42, to scribe a circle on the pipe m, is pivotally attached to the lower end portion of the arm by a screw stud 43 and an applied knurled thumb nut, 44. Normally, the holder 4|V is frictionally clamped on the arm 39 where positioned. In the arm 39. is an intermediate joint 25 having a pivot in the form of a knurled thumb screw 46 that frictionally holds the joint from pivotal movement.

By turning the sleeve 3d by means of the knob 31, the pencil 42 will scribe a circular line on the pipe o: and at the same time the sleeve 3S will float on the shaft 28 and thus always keep the pencil in contact with the pipe Referring now in detailY to the instrument B, wherein. the, parts, thereof that correspond to like parts throughout the several views in Figs.

l, 3 and 4 are given the same reference numeral followed by a prime. The shaft 28 is rigidly secured to the shaft 28, in parallel arrangement by a Spanner 41, comprising an outer section 58 and an inner section 49. On the outer end of the section 48 is a sleeve 5|) and on the outer end of the section 49 is a sleeve 5|. These two sleeves 50 and 5| are identical with the sleeve 34 and the ears and knurled thumb screw are designated by the numerals 52 and 53, respectively. The sleeves 5|! and 5| are applied to the upper end portions of the shafts 28 and 28' and are normally clamped thereon. rFhe Spanner sections i8 and 4e are in overlapped arrangement and connected, for endwise adjustment, to vary the distance between the two shafts 23 and 28 by a lenurled thumb screw 5d that extends through a longitudinal slot 55 in the Spanner section 49 and has threaded engagement with the section t8. For holding the two Spanner sections `|18 and 139- for straight line movement and aligned, a second lnurled screw 5t extends` through a longitudinal slot 51 in the section 43 and has threaded engagement with the section 59, see Fig. 2.

When the instrument A is to be used to scribe a circle on the pipe x, the arm 39 of the instrument B may be turned on the opposite side of the shaft 28 from that shown, or the instrument B removed by detaching the spanner 41 from the shaft 28. If desired, one compass may be dispensed with and the other mounted on either shaft 28 or 28.

Referring now to the instrument C shown in Figs. '7 and 8, which has a base 58 similar to the base l@ and has on its flanges hooks 59 to which a clamping device similar to the one shown for instrument A may be attached to secure the base 53 on a pipe y: Integral with the righthand flange of the base 58 is an upstanding bearing 6D.

A clamp 5| is applied to the bearing 62 and includes an annular member 62 having a pair of lugs 63 between `which the bearing 6G extends. These lugs G3 are pivotally attached to the bearing 5S by a bolt 64 that extends through aligned holes in the bearing $6 and the lugs 63. The bolt 64 has an enlarged annular head E5 loose in the hole in the left-hand lug 63, as viewed in Fig. 8, impinges the bearing 60 and holds the same frictionally clamped against the right-hand lug 63.. A nut 66 has threaded engagement with the outer end portion of the bolt 643 and impinges the outer side of the right-hand lug d3 as a base of resistance.

A bolt 61 projects through a hole in the clamp member 6| at the axis thereof and has a head 61 that impinges the outer side of said clamp member. On the outer end of the bolt 61 is a screwthreaded stud 68 of reduced diameter. The clamp 6| further includes a pair of discs 69 and 1|) turnably mounted on the bolt 61 and have in their opposing faces half seats 1|. A shaft 12 is mounted in half seats 1| at its lower end portion and has a pointed lower end 12. A knurled thumb nut 13 applied to the screw stud 63 impinges the outer disc |59v and holdsthe discsv 6.9v and 10 clamped onto the shaft. 12 and with the disc 10 frictionally clamped onto the clamp member 62. The shaft 12 extends loosely through a transverse hole 14 in the bolt 61 of a diameter larger than the diameter of the shaft 12,

A sleeve is mounted on the shaft 12 to float axially thereon. and to turn about the axis of said shaft. This sleeve carries an arm having a pencil holder which is identical with like parts in Figs. 1, 3 and 4 and are given the same reference numerals followed by the letter a. The shaft 12 in the instrument C is capable of being tilted laterally in addition to its swinging movement.

The tilting feature of instrument IC is designed to accomplish what is known in the pipe trades as eccentric branch layouts. To mount instrument C on pipe y to scribe a circle thereon, first clamp base 58 temporarily onto said pipe by means of a clamping device, similar to the one shown in instruent A attached to the hooks 59. By use of knurled nut 73 and clamping disks, set shaft at 90 degrees, or approximately so, with axis of pipe y. Rotate scriber assembly around shaft 12 until scriber point is directed on the opposite side of shaft 12 to that of bolt 64. Set scriber point to radius of smaller or branch pipe. Loosen nut 86 and tilt shaft 72 toward bolt 64 and at the same time, with scriber point still in the same above mentioned position of rotation, slide scriber assembly along shaft 72 until said scriber point touches surface of pipe y. Keep tilting shaft 7L and at the same time keep point of scriber in Contact with surface of pipe 1f by moving scriber assembly axially along shaft 12 until said scriber point reaches a point of tangency with circumference of p-ipe y. Tighten nut 66 firmly. Loosen knurled nut 13 and swing shaft 72 to desired angle and at the same time move shaft 72 axially toward pipe y until point 12 is almost touching surface of said pipe. v Tighten knurled nut 73 again. The instrument is now ready to use as far as tilting and swing angle adjustments are concerned. On surface of pipe y, locate the point through which axis of branch pipe Will pass. Loosen base 58 from pipe y and move said base along surface of said pipe until point 72' coincides with above mentioned located point. Tighten base 58 to pipe in this location and instrument is now ready tc scribe circle on pipe y. It might be stated here that eccentric vbranch layouts can also be made with the combination of instrument A and B in Figure 1. With spanner free on shaft 28 and by using shaft 28 as a center and the Spanner assembly as a radius, the shaft 28' may be swung to either side as far as desired and Spanner clamped to shaft 28. Then shaft 28 can be reset axially until its pointed end 3| touches surface of pipe again. Base l 0 is loosened from pipe x and moved along surface of said pipe until point 3| coincides with prelocated point on surface of pipe w. said prelocated point to be that through which axis of branch pipe will pass. Base I0 is then tightened against surface of pipe .'c. Instrument C can also be substituted for instrument A in Fig. 1.

In Fig. 9 is shown a magnetic base 15 for attaching instruments of the class described to a piece of work. A fragment of the shaft 16 is attached to the base 15 by a clamp 11. On each side of the base I5 is a hook 78, only one of which is shown, for attaching a pair of chains of a clamping device, as shown in Fig. 5, in case the base 15 is applied to a piece of work of non-magnetic material.

From the foregoing, it must be evident that the invention herein disclosed is capable of a large range of modification within the spirit of the invention herein disclosed and claimed.

What I claim is:

1. In an instrument of the class described, a base in the form of an angle bar having on one of its flanges a bearing, a member pivoted to the bearing to turn about an axis parallel to the apex of the base, a clamp pivoted to said member to turn about an axis that extends transversely of the base, said base having a notch in one end portion at its apex, a shaft held by the clamp for endwise adjustment and for swinging movement with the clamp into and out of the notch in the plane of the apex of the base, said member permitting swinging movement of the shaft with the clamp transversely of the base to project the shaft through the notch, and a member adjustably mounted on the shaft.

2. In an instrument of the class described, a base in the form of an angle bar having a bearing xed to one of its flanges, a member pivoted to the bearing to turn about an axis parallel to the apex of the base, a pair of jaws, adjustable means connecting the jaws and pivotally attaching the same to said member` to turn about an axis extending transversely of the base, said base having a notch in one end portion at its apex, a shaft held by the jaws to be turned thereby into and out of said notch, said adjustable means being operable t0 clamp the jaws onto the shaft and also clamp one of the jaws onto said member, and a scriber carried by the shaft.

EDWARD E. NORRIS.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 233,424 McBean Oct. 19, 1880 784,903 Stemmrich Mar. 14, 1905 804,867 Stowe Nov. 7, 1905 1,286,770 Rashkovsky Dec. 3, 1918 1,660,616 James Feb. 28, 1928 1,698,154 Day Jan. 8, 1929 1,743,024 Clark Jan. 7, 1930 1,991,117 Porteous et al Feb. 12, 1935 2,436,542 Black Feb. 24, 1948 2,464,901 Sturm Mar. 22, 1949 FOREIGN PATENTS Number Country Date 57,979 Sweden Dec. 16, 1924 545,026 Germany Feb. 26, 1932 

